MySQL Query Error, sql: (SELECT sell_id,price,unit,property_sys_select,property_sys_input,img_path,imp_status,description,user_name FROM web_sell_a WHERE sell_id IN(11413353,23075041)) UNION (SELECT sell_id,price,unit,property_sys_select,property_sys_input,img_path,imp_status,description,user_name FROM web_sell_5 WHERE sell_id = 42152197 ) UNION (SELECT sell_id,price,unit,property_sys_select,property_sys_input,img_path,imp_status,description,user_name FROM web_sell_8 WHERE sell_id IN(55871871,55871878,55871874)) UNION (SELECT sell_id,price,unit,property_sys_select,property_sys_input,img_path,imp_status,description,user_name FROM web_sell_9 WHERE sell_id IN(11280640,11420595,11420778,11434896)), ErrMsg: MySQL server has gone away